TW201316139A - Microlithography device and method for cooling components in lithography device - Google Patents

Abstract

A lithography apparatus includes an element and a local area cooler for applying a local cooling load to the element. The local cooler has a gas passage including a flow restriction upstream of the element and configured to direct an air flow exiting the flow restriction to cool a surface of the element.

Description

Microlithography device and method for cooling components in lithography device

The present invention relates to a lithography apparatus and a method of cooling components in a lithography apparatus.

A lithography apparatus is a machine that applies a desired pattern onto a substrate, typically applied to a target portion of the substrate. The lithography apparatus can be used, for example, in the fabrication of integrated circuits (ICs). In that case, a patterned device (which may be referred to as a reticle or a proportional reticle) may be used to create a circuit pattern to be formed on individual layers of the IC. This pattern can be transferred onto a target portion (eg, a portion containing a die, a die, or a plurality of dies) on a substrate (eg, a germanium wafer). Transfer of the pattern is typically performed via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of sequentially adjacent adjacent target portions. Known lithography apparatus includes a so-called stepper in which each target portion is irradiated by exposing the entire pattern to a target portion at a time; and a so-called scanner in which a given direction ("scanning" direction) Each of the target portions is irradiated by scanning the pattern via the radiation beam while scanning the substrate in parallel or anti-parallel in this direction. It is also possible to transfer the pattern from the patterned device to the substrate by imprinting the pattern onto the substrate.

The machine can be a machine that fills the space between the final assembly of the projection system and the substrate with a relatively high refractive index liquid (eg, water). In one embodiment, the liquid is distilled water, but another liquid can be used. Another fluid may be suitable, particularly a wetting fluid, an incompressible fluid, and/or a refractive index higher than A fluid having a refractive index of air (ideally, higher than the refractive index of water). Fluids that exclude gases are particularly desirable. The point of this situation is to achieve imaging of smaller features because the exposure radiation will have a shorter wavelength in the liquid. (The effect of the liquid can also be considered to increase the effective numerical aperture (NA) of the system and also increase the depth of focus). Other infiltrating liquids have been proposed, including water in which solid particles (e.g., quartz) are suspended, or liquids having nanoparticle suspensions (e.g., particles having a maximum size of up to 10 nanometers). The suspended particles may or may not have a refractive index similar to or the same as the refractive index of the liquid in which the particles are suspended. Other liquids which may be suitable include hydrocarbons such as aromatic, fluorohydrocarbons and/or aqueous solutions.

Instead of a circuit pattern, the patterned device can be used to create other patterns, such as a color filter pattern or a dot matrix. Instead of a conventional mask, the patterned device can include a patterned array that includes an array of individually controllable components that produce circuitry or other suitable patterns. The advantage of this "maskless" system over conventional mask-based systems is that the pattern can be provided and/or changed more quickly and at less cost.

Thus, a maskless system includes a programmable patterning device (eg, a spatial light modulator, a contrast device, etc.). The programmable patterning device is programmed (eg, electronically or optically) to form a desired patterned beam using an individually controllable array of components. Types of programmable patterning devices include micromirror arrays, liquid crystal display (LCD) arrays, grating light valve arrays, and the like.

For example, PCT Patent Application Publication No. WO 2010/032224 and U.S. Patent Application Publication No. US 2011-0188016 (the entire contents of which are incorporated herein by reference) As disclosed herein, in lieu of conventional masks, the modulator can be configured to expose an exposed area of the substrate to a plurality of beams modulated in accordance with a desired pattern. The projection system can be configured to project the modulated beam onto the substrate and can include a lens array to receive the plurality of beams. The projection system can be configured to move the lens array relative to the modulator during exposure of the exposed area.

The lithography apparatus may be an EUV apparatus that uses extreme ultraviolet light (for example, having a wavelength of 5 nm to 20 nm).

Many of the elements in a lithography apparatus can have undesirable thermal loadings applied to such elements. This load may be the result of the projection of the projected beam onto the component, the result of current flow, and the like. This localized heating is not ideal because it can cause local deformation and thereby cause possible imaging errors. In addition, if, for example, the top plate of the projection system through which the projection beam passes (for example, the structure associated with the small environment of FIGS. 4 and 5) has a non-uniform temperature, this situation may cause a change in refractive index or a difference from the desired Changes in shape, thus directly leading to possible imaging errors. For example, if the temperature change is on the substrate stage, this situation can result in deformation of the substrate and thereby cause possible imaging errors.

In a lithography apparatus, a cooling liquid flowing in one or more passages in the vicinity of an external heating load may be used. A cooling medium can be supplied to the element at a temperature below the set point temperature of a component. This situation causes rapid cooling. However, one difficulty is that the low temperature of the cooling medium in the conduit to the component can have an undesirable effect on the temperature of one or more components passing through the conduit. In a In addition, the cooling medium can be supplied at the set point temperature in the system. However, in this configuration, it may be difficult to bring the component to the set point temperature forever. Alternatively or additionally, the cooling medium exiting the component in the conduit has a temperature above the set point temperature, and this condition can detrimentally affect one or other components (eg, one or more components through which the conduit passes).

There is a need to provide a cooling system for a lithography apparatus. In an embodiment, the cooling system processes at least one of the above problems associated with the cooling medium.

According to one aspect of the present invention, a lithography apparatus is provided, the lithography apparatus comprising: an element; a local area cooler for applying a local cooling load to the element, the local cooler comprising: A gas passage includes a flow restriction upstream of the element and configured to direct an air flow exiting the flow restriction to cool a surface of the element.

According to one aspect of the invention, a method of cooling an element in a lithography apparatus is provided, the method comprising: providing a gas flow through a gas passage and forcing the gas through a flow restriction to expand and cool the gas; The expanded and cooled gas cools one surface of the element to be cooled.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings,

FIG. 1 schematically depicts a lithography apparatus in accordance with an embodiment of the present invention. The apparatus comprises: - a lighting system (illuminator) IL configured to adjust a radiation beam B (eg, UV radiation or DUV radiation); a support structure (eg, a reticle stage) MT configured to support a patterned device (eg, reticle) MA and coupled to a first location configured to accurately position the patterned device in accordance with certain parameters a substrate (eg, a wafer table) WT that is configured to hold a substrate (eg, a resist coated wafer) W and is coupled to be configured to accurately position the parameter based on certain parameters a second positioner PW of the substrate; and a projection system (eg, a refractive projection lens system) PS configured to project a pattern imparted to the radiation beam B by the patterned device MA to a target portion C of the substrate W ( For example, one or more crystal grains are included).

The illumination system can include various types of optical elements for guiding, shaping, or controlling radiation, such as refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic, or other types of optical elements, or any combination thereof.

The support structure holds the patterned device. The support structure holds the patterned device in a manner that depends on the orientation of the patterned device, the design of the lithographic device, and other conditions, such as whether the patterned device is held in a vacuum environment. The support structure can use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterned device. The support structure can be, for example, a frame or table that can be fixed or movable as desired. The support structure ensures that the patterned device is, for example, in a desired position relative to the projection system. Any use of the terms "proportional mask" or "reticle" herein is considered synonymous with the more general term "patterned device."

The term "patterned device" as used herein shall be interpreted broadly to refer to any device that can be used to impart a pattern to a radiation beam in a cross-section of a radiation beam to create a pattern in a target portion of the substrate. Should pay attention to, for example In contrast, if the pattern imparted to the radiation beam includes a phase shifting feature or a so-called auxiliary feature, the pattern may not exactly correspond to the desired pattern in the target portion of the substrate. Typically, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device (such as an integrated circuit) created in the target portion.

The patterned device can be transmissive or reflective. Examples of patterned devices include photomasks, programmable mirror arrays, and programmable LCD panels. Photomasks are well known in lithography and include reticle types such as binary, alternating phase shift and attenuated phase shift, as well as various hybrid mask types. One example of a programmable mirror array uses a matrix configuration of small mirrors, each of which can be individually tilted to reflect the incident radiation beam in different directions. The tilted mirror imparts a pattern in the radiation beam reflected by the mirror matrix.

The term "projection system" as used herein shall be interpreted broadly to encompass any type of projection system suitable for the exposure radiation used or other factors such as the use of a immersion liquid or the use of a vacuum, including refraction, reflection, Reflective, magnetic, electromagnetic, and electrostatic optical systems, or any combination thereof. Any use of the term "projection lens" herein is considered synonymous with the more general term "projection system".

As depicted herein, the device is of the transmissive type (eg, using a transmissive reticle). Alternatively, the device can be of the reflective type (eg, using a programmable mirror array of the type mentioned above, or using a reflective mask).

The lithography device can be of the type having two or more stages (or stages or supports), for example, two or more substrate stages, or one or more Combination of substrate stages with one or more sensor stages or gauges. In such "multi-stage" machines, additional stations may be used in parallel, or preliminary steps may be performed on one or more stations while one or more other stations are used for exposure. The lithography apparatus can have two or more patterned devices (or stages or supports) that can be used in parallel similar to the substrate stage, the sensor stage, and the measurement stage.

The lithography apparatus can also be of the type wherein at least a portion of the substrate can be covered by a liquid (eg, water) having a relatively high refractive index to fill the space between the projection system and the substrate. The immersion liquid can also be applied to other spaces in the lithography apparatus, for example, the space between the reticle and the projection system. Infiltration techniques are well known in the art for increasing the numerical aperture of a projection system. As used herein, the term "wetting" does not exclusively mean that a structure such as a substrate must be immersed in a liquid, but rather that the liquid can be located between the projection system and the substrate and/or reticle during exposure. This situation may or may not involve the immersion of a structure such as a substrate in a liquid. Reference numeral IM shows where the device for implementing the wetting technique can be located. The device may include a supply system for immersing the liquid, and a sealing member for containing the liquid in the region of interest. Optionally, the device can be configured such that the substrate table is completely covered by the immersion liquid.

Referring to Figure 1, illuminator IL receives a radiation beam from radiation source SO. For example, when the radiation source is a quasi-molecular laser, the radiation source and the lithography device can be separate entities. Under such conditions, the source of radiation is not considered to form part of the lithography apparatus, and the radiation beam is transmitted from the source SO to the illuminator by means of a beam delivery system BD comprising, for example, a suitable guiding mirror and/or beam expander. IL. In other cases, for example, when the source of radiation is a mercury lamp, the source of radiation may be an integral part of the lithography apparatus. The radiation source SO and illuminator IL together with the beam delivery system BD (when needed) may be referred to as a radiation system.

The illuminator IL can include an adjuster AD for adjusting the angular intensity distribution of the radiation beam. In general, at least the outer radial extent and/or the inner radial extent (commonly referred to as σ outer and σ inner, respectively) of the intensity distribution in the pupil plane of the illuminator can be adjusted. In addition, the illuminator IL may include various other components such as the concentrator IN and the concentrator CO. The illuminator can be used to adjust the radiation beam to have a desired uniformity and intensity distribution in its cross section. Similar to the radiation source SO, it may or may not be considered that the illuminator IL forms part of the lithography apparatus. For example, the illuminator IL can be an integral part of the lithography apparatus or can be an entity separate from the lithographic apparatus. In the latter case, the lithography apparatus can be configured to allow the illuminator IL to be mounted thereon. The illuminator IL is detachable and may be provided separately (eg, provided by a lithography apparatus manufacturer or another supplier), as appropriate.

The radiation beam B is incident on a patterned device (e.g., reticle) MA that is held on a support structure (e.g., a reticle stage) MT, and is patterned by the patterned device. In the case where the patterned device MA has been traversed, the radiation beam B is transmitted through the projection system PS, which projects the beam onto the target portion C of the substrate W. With the second positioner PW and the position sensor IF (for example, an interference measuring device, a linear encoder or a capacitive sensor), the substrate table WT can be accurately moved, for example, to position different target portions C to the radiation beam. In the path of B. Similarly, the first locator PM and another position sensor (which is not explicitly depicted in Figure 1) can be used, for example, at The patterned device MA is accurately positioned relative to the path of the radiation beam B after mechanical scavenging of the mask library or during scanning. In general, the movement of the support structure MT can be achieved by means of a long stroke module (rough positioning) and a short stroke module (fine positioning) forming the components of the first positioner PM. Similarly, the movement of the substrate table WT can be achieved using a long stroke module and a short stroke module that form the components of the second positioner PW. In the case of a stepper (relative to the scanner), the support structure MT can be connected only to the short-stroke actuator or can be fixed. The patterned device MA and the substrate W can be aligned using the patterned device alignment marks M1, M2 and the substrate alignment marks P1, P2. Although the illustrated substrate alignment marks occupy dedicated target portions, the marks may be located in the space between the target portions (the marks are referred to as scribe line alignment marks). Similarly, where more than one die is provided on the patterned device MA, the patterned device alignment mark can be located between the dies.

The depicted device can be used in at least one of the following modes:

1. In the step mode, the support structure MT and the substrate table WT are kept substantially stationary (i.e., a single static exposure) while the entire pattern to be imparted to the radiation beam is projected onto the target portion C at a time. Next, the substrate stage WT is displaced in the X and/or Y direction so that different target portions C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure.

2. In the scan mode, when the pattern to be given to the radiation beam is projected onto the target portion C, the support structure MT and the substrate stage WT (i.e., single dynamic exposure) are synchronously scanned. The speed of the substrate table WT relative to the support structure MT can be determined by the magnification (reduction ratio) and the image inversion characteristic of the projection system PS. Degree and direction. In the scan mode, the maximum size of the exposure field limits the width of the target portion in a single dynamic exposure (in the non-scanning direction), and the length of the scanning motion partially determines the height of the target portion (in the scanning direction).

3. In another mode, the support structure MT is held substantially stationary while the pattern to be imparted to the radiation beam is projected onto the target portion C, thereby holding the programmable patterning device and moving or scanning the substrate table WT . In this mode, as in other modes, a pulsed radiation source is typically used, and the programmable patterning device is updated as needed between each movement of the substrate table WT or between successive pulses of radiation during a scan. This mode of operation can be readily applied to matte lithography utilizing a programmable patterning device such as a programmable mirror array of the type mentioned above.

Combinations of the modes of use described above and/or variations or completely different modes of use may also be used.

FIG. 2 schematically illustrates a local cooler 100 in accordance with an embodiment. The local cooler 100 uses the Joule-Thomson effect. The Joule-Thomson effect describes a temperature change due to sudden expansion of the actual gas. Many gases, such as carbon dioxide and nitrogen (and, of course, air), become cold during expansion. Other gases such as helium and hydrogen will warm up. In one embodiment, carbon dioxide is used. In one embodiment, extremely clean dry air (i.e., sometimes referred to as XCDA and widely used in filtered and dehumidified air in lithography apparatus) is used.

The described embodiment assumes that the device acts as a cooler. However, an embodiment of the invention applies equally to a heater (eg, to compensate for localized colds that may be experienced by evaporation of the infiltrating liquid from the substrate in the wetting device, for example) but). An example of a gas that heats up during expansion is helium.

An advantage of this cooler over conventional liquid coolers is that the coolant gas can typically be supplied to and cooled from the component to be cooled at a temperature close to the set point temperature of the component 120 to be cooled and/or the device. Agent gas. Additionally, the gas that has been used for cooling can be reused in the device. For example, the gas can be reused for a purge operation to evict unwanted gases and/or contaminants from a region (eg, an environment surrounding the reticle or a region through which the radiation beam of the position measurement system passes). For example, the gas can be reused as a component of an air knife, a contactless seal or a drying station. Reuse may require, for example, temperature adjustment by the conditioned cooling liquid used to cool the projection system, and/or filtration.

As illustrated in FIG. 2, the local cooler includes a gas passage 110 and a flow restriction 115. As the gas flows through the gas passage 110 and through the flow restriction 115, a pressure drop is created. According to the Joule-Thomson effect, this pressure drop causes sudden expansion of the gas and cooling of the gas. The cooled gas is then directed to cool the surface of the component 120 to be cooled. In an embodiment, this cooling is achieved by directing a flow of cooling gas over the surface of the element to be cooled 120. In one embodiment, a cooled gas is used to cool the conduit from which heat is extracted from the surface of the element to be cooled 120. This cooling can be carried out by direct or indirect contact of the cooling gas with the surface of the element to be cooled 120.

In an embodiment, the local cooler includes one or more passages 110 having corresponding flow restrictions 115. The expanded gas of each passage 110 can be directed to different regions of the surface of the component 120 to be cooled. In this way, a local cooling load can be applied at different locations, and the appropriate control can be used to make the element The entire surface of the piece 120 remains isothermal.

In an embodiment, more than one flow restriction 115 is provided in the passageway 110. The temperature of the gas in contact with the surface of element 120 will increase due to the surface such that the cooling load closest to flow restriction 115 is greater than the cooling load that is further from flow restriction 115. To compensate for this situation and allow a more uniform cooling load to be applied to the large surface, more than one flow restriction 115 may be provided in series such that the gas expands at least twice, thereby being cooled twice. This situation is illustrated in Figure 2 by a second flow restricting member 115A in dotted lines. Any number of flow restrictors 115, 115A can be provided in series in the gas passage 110.

A cooling controller 130 is provided to control the gas pressure drop across the flow restrictors 115, 115A and thereby control the magnitude of the local cooling load. In the embodiment of Figure 2, the flow restricting members 115, 115A are variable flow restricting members. The cooling controller 130 is adapted to control the magnitude of the flow restriction (e.g., the size of the slit or hole through which the gas passes) and thereby control the magnitude of the pressure drop.

The cooling controller 130 can control the magnitude of the pressure drop (eg, the size of the flow restriction 115, 115A) in any manner. In an embodiment, the cooling controller 130 operates based on feedforward (where the controller knows the thermal load expected to be applied to the surface of the component to be cooled 120 and a subsequent temperature rise is expected).

In an embodiment, as illustrated in Figure 2, the cooling controller 130 controls the pressure drop in a feedback manner. In an embodiment, the controller is based on the temperature of (for example, the surface) of the component 120 sensed by the (surface) temperature sensor 140. Thus, if the temperature of the surface of element 120 rises above a certain (eg, predetermined) value, controller 130 may increase the pressure drop (eg, by reducing the flow restriction) The size), thereby increasing the magnitude of the local cooling load. Conversely, if the surface temperature of element 120 rises such that a lower cooling load is required, controller 130 may reduce the low pressure drop by increasing the magnitude of flow restriction 115, 115A and thereby reducing the magnitude of the local cooling load.

In the embodiment of FIG. 2, a mass flow controller 150 is provided that provides a substantially constant flow of gas along the passageway 110. Mass flow controller 150 (which may be incorporated into pump 151) is configured to provide a certain (eg, predetermined) flow of gas through passageway 110. The controller 130 individually controls the magnitude of the cooling load by adjusting the variable flow restriction 115. As will be described with reference to FIG. 3, in an embodiment, the mass flow controller 150 can be instructed by the controller 130 to adjust the magnitude of the airflow. By varying the pressure on the upstream side of the flow restricting members 115, 115A, the magnitude of the pressure drop across the flow restricting members 115, 115A can be varied. In addition, higher mass flow rates result in higher heat transfer coefficients and increased heat capacity of the gas stream.

As described above, the gas can be carbon dioxide or XCDA or nitrogen and is supplied from source 160. The gas at the end of the passage reaches the outlet 170 downstream of the surface of the element to be cooled 120. In an embodiment, the gas treatment system 180 is coupled to the outlet 170. Gas treatment system 180 can use gas from passageway 110. This use may be for purposes other than as a coolant. Examples of the use of the gas include: a space for purifying undesired gases and/or particles (for example, a space through which the measuring beam of the micro-environment or self-measurement system passes) to form a gap between the two surfaces. Contact the seal and/or to dry the wetted surface.

In an embodiment, the gas injection outlet 170 is recirculated to the gas source 160. In one embodiment, the gas exit outlet 170 is allowed to pass to the environment in which the lithographic apparatus is located. The outlet 170 can be connected to an exhaust system external to the lithography apparatus.

Heat exchanger 190 can be provided upstream of flow restrictors 115, 115A. For example, heat exchanger 190 can use a liquid as a thermal transfer medium. Heat exchanger 190 brings the temperature of the gas sufficiently close to the reference temperature of the device such that one or more conduits forming passage 110 will typically be at a temperature near the reference temperature of the component and/or device.

A downstream temperature sensor 200 can be provided to measure the temperature of the gas in the gas passage 110 downstream of the element 120 (eg, the surface of the element 120). The cooling controller 130 can monitor the temperature measured by the downstream temperature sensor 200. This temperature can be used in the control loop. For example, the cooling controller 130 can be adapted to adjust the pressure drop based on the temperature measured by the downstream temperature sensor 200 (eg, in a feedback manner). Alternatively or additionally, the temperature measured by downstream temperature sensor 200 can be used to help ensure that the gas downstream of element 120 is typically near the set point temperature of the element and/or device.

In an embodiment, a pressure sensor 210 is provided to measure the gas pressure in the passage 110 upstream of the flow restriction 115, 115A. The output of the pressure sensor 210 can be provided to a limit controller (which can be a component of the cooling controller 130). The limit controller may limit the gas pressure in the passage 110 upstream of the flow restriction 115, 115A when the pressure measured by the pressure sensor 210 exceeds a certain value. For example, the limit controller can control the size of the flow restriction 115, 115A and/or instruct the mass flow controller 150 to reduce the mass flow rate of the gas in the passage 110, and/or initiate (or) pressure adjustment. The throttle adjusts the gas pressure in the passage 110 upstream of the flow restriction. In an embodiment, the cooling controller 130 can adjust the pressure of the pressure regulator, thereby controlling the pressure drop across the flow restricting members 115, 115A.

In an embodiment, the cooling controller 130 can control the mass flow controller 150 and/or the flow restrictors 115, 115A based at least in part on the pressure measured by the pressure sensor 210.

As illustrated in FIG. 2, mass flow controller 150 can send a signal to cooling controller 130. For example, the signal may be related to system limitations, such as information regarding the maximum mass flow achieved, or the mass flow controller 150 may not increase the mass flow beyond a certain point (eg, beyond the current rate). Alternatively or additionally, the mass flow rate may be increased when a maximum pressure drop is achieved to further increase the cooling capacity. The cooling controller 130 may use feedback from one or more of the sensors 140, 200, 210 to change the policy or provide feedback to the user that the system limits have been reached.

Figure 3 illustrates an additional embodiment. The embodiment of Figure 3 is identical to the embodiment of Figure 2 except as described below.

In the embodiment of FIG. 3, the cooling controller 130 controls the mass flow controller 150. The pressure drop across the flow restriction 115, 115A is varied, at least in part, by adjusting the mass flow controller 150 to vary the flow of gas through the passageway 110. In this embodiment, the flow restricting members 115, 115A can be variable flow restrictors (in this case, the cooling controller 130 can vary the pressure drop by varying the mass flow rate and the flow defining size). In an embodiment, the flow restricting members 115, 115A can be fixed restraints such that the pressure drop is controlled only by varying the mass flow rate through the flow passages 110.

A pressure regulator upstream of the flow restricting members 115, 115A can be used to vary the pressure in the gas passage 110 upstream of the flow restricting members 115, 115A. The pressure drop across the flow restricting members 115, 115A can be varied by varying the setting of the pressure regulator.

The cooling system is extremely flexible and has a relatively simple control that does not involve cooling the flow of the medium at temperatures that deviate from the set point temperature. The response time of the system is superior to that of a liquid-based closed loop cooling system that suffers from thermal inertia. That is, the time lag between heating the liquid (to extract energy) is greater due to the higher heat capacity of the liquid than for the gas.

The cooling system may not require a temperature adjustment setting as a liquid-based cooling system. However, a liquid based cooling system can extract more thermal energy than the cooling system described herein. In an embodiment, there is no need for a return path to recirculate the gas. In this case, the number of hoses in the hose bundle can be reduced. This situation is beneficial in terms of volume and hardness and dynamic performance issues.

As mentioned above, after a gas has been used to cool the surface of element 120, the gas can be used in an efficient manner to handle other problems.

In addition, the liquid in the lithography apparatus is generally not ideal. In some areas, the presence of liquids must be avoided. In other areas, leakage of liquid can cause problems, and gas leakage is less of a problem.

The following shows that for a flow rate of 100 standard liters per minute (ambient pressure and 0 ° C), the cooling system has a passage 110 of size 1 x 200 x 300 mm, a gas flow rate of less than 10 meters per second and a Reynolds number (Reynolds number) Below 2200, a thermal transfer coefficient of about 100 W/m ² K is achieved for XCDA, and a thermal transfer coefficient of about 65 W/m ² K is achieved for CO ₂ . The data for carbon dioxide and air shows that at 22 ° C, the Joule-Thomson coefficient is about 1.080 g erb/bar for CO ₂ , and the Joule-Thomson coefficient for XCDA is about 0.237 g erb/bar. . This situation demonstrates that heat transfer in the above region (1 x 0.2 meters x 0.3 meters) with a pressure drop of about 4 bar can cause an average heat transfer in the heat transfer zone, which is about XCDA. 50 W/m ² , and for CO ₂ , the average heat transfer is about 130 W/m ² . The limiting factor is the heat capacity of the gas stream such that the XCDA gas stream has a cooling capacity of about 2.2 W and for CO _{2 a} cooling capacity of about 11 W.

Although the above demonstrates that the amount of heat extracted by the cooling system may not be too large, this amount is the amount of cooling used for certain components in the lithography apparatus, particularly the components described above.

Cooling system 100 can be used to cool any of the components of the lithography apparatus. Examples include components of the substrate table WT, such as actuators of the substrate table WT, particularly for a substrate table WT that is adapted for use with a substrate W having a diameter (or equivalent size) of 450 mm or 300 mm. The invention is not limited to the size/shape of the substrate. The substrate stage WT for the large substrate W may include one or more manipulators for planarizing the surface of the substrate W, and the size of the manipulator may be such that a current flowing in the manipulator is applied to the manipulator The heat load is low enough to be extracted by the cooling system described above. The cooling system can be used to locally cool the substrate, for example, from the bottom surface of the substrate support for the substrate W. A cooling system can be used to cool the components of the projection system PS, including the top plate.

The cooling system 100 can be used to cool a sensor or station such as a lithography device Set the components of the encoder. The cooling system 100 can be used to cool a component of a lithography apparatus or EUV lithography apparatus using a patterned array or modulator for patterning a projection beam (eg, a lens array for receiving a plurality of beams from the modulator) . One or more conduits for providing gas to and from the element may be flexible due to the flow restriction 115 provided upstream of the element.

Cooling system 100 can be used to cool the top plate described below with reference to Figures 4 and 5. The top plate may be locally heated by the support structure MT motor and/or the projection beam PB and/or the reticle reference (which may be heated by the laser during measurement and then radiated to the top plate).

In a lithographic projection apparatus, it is desirable to maintain a controlled internal gas environment in the region of the patterned device MA. The internal gaseous environment in the region of the patterned device can be controlled to prevent sensitive components and/or air from interfering with the radiation beam and/or the sensitive components of the patterned device. The internal gaseous environment will typically be substantially isolated from the external zone but not completely blocked. A gas supply system having an outlet to the internal gaseous environment can be provided and configured to maintain the overpressure in the internal gaseous environment. Overpressure depresses the gas stream (e.g., a substantially constant gas stream) from the internal gas environment, i.e., to purify the environment. The outward airflow helps prevent the influx of contaminants. The outward flow may be supplied to the passage to pass through a leak-tight seal, for example, by opposing flow defining a surface. In addition, there is a need for a path through which one or more of the encoder and/or interferometer beams are passed without contamination and having one or more substantially constant properties.

Figure 4 depicts how the internal gas can be achieved in the area above the support MT An embodiment of the control of the body environment 4. The internal gas environment 4 in this example is located between the patterned device MA and the support MT on one side and on the other side (and the surrounding hardware) of the patterned device MA and the illumination system IL on the other side 2 between. Thus, the depicted internal gas environment 4 is the volume through which the radiation beam will pass before it encounters the patterned device MA.

In the example of FIGS. 4 and 5, a gas supply system 5 is provided to supply gas to the internal gaseous environment 4 via the outlet 7. The gas can be supplied under controlled composition and/or at a controlled flow rate. The gas can come from the outlet 170 of the cooling system. The overpressure is maintained within the internal gaseous environment 4 as appropriate. Overpressure causes an outward flow, as indicated schematically by arrow 6. The gas supply system 5 and/or the outlet 7 can be mounted on or in the patterned device support MT (as shown) and/or mounted on or in the assembly above and/or below the patterned device support MT. For example, the gas supply system 5 and/or the outlet 7 can be mounted on or in the final assembly 2 of the illumination system IL. Alternatively or additionally, the gas supply system 5 and/or the outlet 7 can be mounted on or in the first component 3 of the projection system PS.

The spatial distribution of flow/speed can be controlled by the first planar component 8A and the second planar component 10A, as shown in FIG. The first planar component 8A is such that the first flow defining surface 8B is presented. The second planar assembly 10A is such that the second flow defining surface 10B is presented.

The flow defining surfaces 8B, 10B of Figure 4 face each other and are configured to resist inward and outward airflow through the gap between the flow defining surfaces 8B, 10B. Resisting the inward airflow will help reduce the pollution of the internal gaseous environment 4. Resistance to the outward flow will assist the gas supply system 5 in maintaining a stable overpressure in the internal gaseous environment 4. The flow defining surfaces 8B, 10B also exhibit a gas The relatively small gap through which the outflow passes. This situation causes an increase in the velocity of gas outflow. An increase in speed will prevent the inward diffusion of pollutants. Again, a higher outflow speed can be beneficial for the following reasons. For example, when the patterned device support MT moves along Y in a first direction, the patterned device support MT creates a lower pressure zone in its wake, the lower pressure zone tends to be conditioned by ambient gases (eg , air) filling, the need to place ambient gases (for example, air) outside the internal gas environment. When the patterned device support MT is then returned to scan in the opposite direction, it is desirable to have an output speed that is at least higher than the scan rate of the patterned device support MT (and ideally higher than the scan rate plus ambient gas inflow to lower The maximum velocity in the pressure zone) in order to reduce or completely avoid significant influx of ambient gases into the internal gaseous environment.

Figure 5 depicts a configuration corresponding to the configuration of Figure 4 except that the internal gas environment 4 is located below the patterned device MA. Thus, the depicted internal gas environment 4 is the volume through which the radiation beam will pass after the patterned device MA has been encountered. The internal gas environment 4 is contained on one side by the support member MT and the patterned device MA, and on the other side by the first component (and surrounding hardware) 3 of the projection system PS (for example, by the above cooling system Contained in a cooled (at least partially transparent) top plate. The support MT in this example includes a first planar component 9A formed in a lower portion thereof. The first planar assembly 9A has a first flow defining surface 9B. The first component of the projection system PS has a second planar component 11A attached to its upper surface. The second planar assembly 11A has a second flow defining surface 11B. The second flow defining surface 11B is configured to face the first flow defining surface 9B.

In both the configuration of Figure 4 and the configuration of Figure 5, arrow 6 schematically shows that gas flows from the outlet 7 of the gas supply system 5 through the central region of the internal gaseous environment 4 and through the flow defining surfaces 8B, 9B, 10B, The gap between 11B flows out to the area outside the internal gas environment 4.

Although reference may be made specifically to the use of lithography devices in IC fabrication herein, it should be understood that the lithographic devices described herein may have other applications, such as manufacturing integrated optical systems, for magnetic domain memory. Lead to detection patterns, flat panel displays, liquid crystal displays (LCDs), thin film heads, and more. Those skilled in the art should understand that in the context of the content of such alternative applications, any use of the terms "wafer" or "die" herein is considered synonymous with the more general term "substrate" or "target portion". . The substrates referred to herein may be processed before or after exposure, for example, in a coating development system (typically applying a resist layer to the substrate and developing the exposed resist), metrology tools, and/or inspection tools. . Where applicable, the disclosure herein may be applied to such and other substrate processing tools. In addition, the substrate can be processed more than once, for example, to create a multilayer IC, such that the term "substrate" as used herein may also refer to a substrate that already contains one or more treated layers.

Although the use of embodiments of the present invention in the context of the content of optical lithography may be specifically referenced above, it should be appreciated that the present invention can be used in other applications (eg, imprint lithography) and not when the context of the content allows Limited to optical lithography. In imprint lithography, the topography in the patterned device defines the pattern created on the substrate. The patterning device can be configured to be pressed into a resist layer that is supplied to the substrate, on which the resist is applied Curing by magnetic radiation, heat, pressure or a combination thereof. After the resist is cured, the patterned device is removed from the resist to leave a pattern therein.

As used herein, the terms "radiation" and "beam" encompass all types of electromagnetic radiation, including ultraviolet (UV) radiation (eg, having or being about 436 nm, 405 nm, 365 nm, 355 nm, 248). Nano, 193 nm, 157 nm or 126 nm wavelengths) and extreme ultraviolet (EUV) radiation (for example, having a wavelength in the range of 5 nm to 20 nm), and particle beams (such as ions) Beam or electron beam).

Although the specific embodiments of the invention have been described above, it is understood that the invention may be practiced otherwise than as described. For example, embodiments of the invention may take the form of a computer program containing one or more sequences of machine readable instructions describing a method as disclosed above; or a data storage medium (eg, semiconductor memory, magnetic A disc or disc) having this computer program stored therein. In addition, two or more computer programs can be used to embody machine readable instructions. Two or more computer programs can be stored on one or more different memory and/or data storage media.

The invention is applicable to substrates having a diameter of 300 mm or 450 mm or any other size.

Any of the controllers described herein may be operable, individually or in combination, when one or more computer programs are read by one or more computer processors located in at least one of the components of the lithography apparatus. The controllers can have any suitable configuration for receiving, processing, and transmitting signals, either individually or in combination. One or more processors are configured to communicate with at least one of the controllers. Example In terms of each, each controller can include one or more processors for executing a computer program comprising machine readable instructions for the methods described above. The controllers may include hardware for storing one or a plurality of data storage media, and/or hardware for storing the media. Thus, the controller can operate in accordance with machine readable instructions of one or more computer programs.

One or more embodiments of the present invention are applicable to any immersion lithography apparatus, regardless of whether the immersion liquid system is provided in the form of a bath, provided only on a localized surface area of the substrate, or unrestricted. In an unrestricted configuration, the immersion liquid can flow over the surface of the substrate and/or substrate table such that substantially the entire uncovered surface of the substrate table and/or substrate is wetted. In this unrestricted infiltration system, the liquid supply system may not limit the rate at which the liquid is wetted or it may provide a limit to the wetting liquid, but does not provide a substantially complete limitation of the wetting liquid.

In one embodiment, the lithography apparatus is a multi-stage device comprising two or more stations located at the exposure side of the projection system, each station containing and/or holding one or more items. In an embodiment, one or more of the stations may hold the radiation sensitive substrate. In one embodiment, one or more of the stations may hold sensors for measuring radiation from the projection system. In one embodiment, the multi-stage device includes a first station (ie, a substrate stage) configured to hold the radiation-sensitive substrate, and a second unit not configured to hold the radiation-sensitive substrate (hereinafter generally And without limitation, it is called a measuring station and/or a cleaning station). The second station can include and/or can hold one or more items other than the radiation sensitive substrate. The one or more items may include one selected from the group consisting of One or more: a sensor for measuring radiation from the projection system, one or more alignment marks, and/or a cleaning device (to clean, for example, a liquid confinement structure).

In an embodiment, the lithography apparatus can include an encoder system for measuring the position, velocity, etc. of the components of the apparatus. In an embodiment, the component comprises a substrate stage. In an embodiment, the component comprises a measuring station and/or a cleaning station. The encoder system can be an addition or replacement to the interferometer system described herein for such stations. An encoder system includes a sensor, sensor, or read head associated with (eg, paired with) a scale or grid. In an embodiment, the movable element (eg, the substrate stage and/or the measuring stage and/or the cleaning station) has one or more dimensions or grids, and the element moves relative to the frame of the lithography apparatus. One or more of a detector, sensor, or read head. One or more of the sensors, sensors or read heads cooperate with the (or such) scale or grid to determine the position, velocity, etc. of the element. In one embodiment, the frame of the lithographic apparatus opposite to the movement of an element has one or more dimensions or grids, and the movable elements (eg, the substrate stage and/or the measurement stage and/or the cleaning station) have The (or such) scale or grid cooperates to determine one or more of the sensor, sensor or read head of the position, velocity, etc. of the component.

The term "lens", as the context of the context permits, may refer to any or a combination of various types of optical elements, including refractive, reflective, catadioptric, magnetic, electromagnetic, and electrostatic optical elements.

The above description is intended to be illustrative, and not restrictive. Therefore, it will be apparent to those skilled in the art that the present invention may be modified without departing from the scope of the appended claims.

2‧‧‧ final assembly

3‧‧‧First component

4‧‧‧Internal gas environment

5‧‧‧ gas supply system

6‧‧‧Outward airflow

7‧‧‧Export

8A‧‧‧ first planar component

8B‧‧‧First flow limited surface

9A‧‧‧ first planar component

9B‧‧‧First flow limited surface

10A‧‧‧Second plane assembly

10B‧‧‧Second flow limiting surface

11A‧‧‧Second plane assembly

11B‧‧‧Second flow limiting surface

100‧‧‧Local Cooler/Cooling System

110‧‧‧ gas path/flow path

115‧‧‧Flow restrictions

115A‧‧‧Second flow restriction

120‧‧‧ components to be cooled

130‧‧‧Cooling controller

140‧‧‧(surface) temperature sensor

150‧‧‧mass flow controller

151‧‧‧ pump

160‧‧‧ gas source

170‧‧‧ gas injection exit

180‧‧‧Gas Disposal System

190‧‧‧ heat exchanger

200‧‧‧Downstream temperature sensor

210‧‧‧ Pressure Sensor

AD‧‧‧ adjuster

B‧‧‧radiation beam

BD‧‧•beam delivery system

C‧‧‧Target section

CO‧‧‧ concentrator

IF‧‧‧ position sensor

IL‧‧‧Lighting system/illuminator

IM‧‧‧Where the device used to implement the infiltration technology can be located

IN‧‧‧ concentrator

M1‧‧‧ patterned device alignment mark

M2‧‧‧ patterned device alignment mark

MA‧‧‧patterned device

MT‧‧‧Support structure/patterned device support

P1‧‧‧ substrate alignment mark

P2‧‧‧ substrate alignment mark

PM‧‧‧First Positioner

PS‧‧‧Projection System

PW‧‧‧Second positioner

SO‧‧‧radiation source

W‧‧‧Substrate

WT‧‧‧ substrate table

1 depicts a lithography apparatus in accordance with an embodiment of the present invention; FIG. 2 schematically illustrates an embodiment of a local cooler; FIG. 3 schematically illustrates an embodiment of a local cooler; FIG. 4 depicts a patterning An internal gas environment on the upper side of the support (in the z-direction) and the first planar component and the second planar component; and Figure 5 depicts the internal gaseous environment on the underside of the support (in the z-direction) and a planar component and a second planar component.

100‧‧‧Local Cooler/Cooling System

110‧‧‧ gas path/flow path

115‧‧‧Flow restrictions

115A‧‧‧Second flow restriction

120‧‧‧ components to be cooled

130‧‧‧Cooling controller

140‧‧‧(surface) temperature sensor

150‧‧‧mass flow controller

151‧‧‧ pump

160‧‧‧ gas source

170‧‧‧ gas injection exit

180‧‧‧Gas Disposal System

190‧‧‧ heat exchanger

200‧‧‧Downstream temperature sensor

210‧‧‧ Pressure Sensor

Claims (14)

A lithography apparatus comprising: an element; a local area cooler for applying a local cooling load to the element, the local cooler comprising: a gas path including one upstream of the element A flow restrictor is configured to direct an airflow exiting the flow restriction to cool one surface of the component. The lithography apparatus of claim 1, wherein the gas passage further comprises an outlet downstream of the element. A lithography apparatus of claim 2, wherein a gas treatment system is coupled to the outlet and configured to primarily use gas from the passage for purposes other than as a coolant. The lithography apparatus of claim 3, wherein the gas treatment system is configured to use the gas from the passage to purify one of the unwanted gases or contaminants or form a contactless seal between the two surfaces Or dry a wet surface. The lithography apparatus of any one of claims 1 to 4, wherein the local cooler further comprises a cooling controller adapted to control a gas pressure drop across the flow restricting member and thereby control The magnitude of the localized cooling load on the component. The lithography apparatus of claim 5, wherein the flow restricting member is a variable flow restricting member, and the cooling controller is configured to control the size of the flow restricting member and thereby control the magnitude of the pressure drop. The lithography apparatus of claim 5 or 6, further comprising a mass flow controller configured to provide a certain airflow through the passage. The lithography apparatus of claim 7, wherein the mass flow controller is configured to maintain the gas flow at a substantially constant magnitude, or wherein the cooling controller is configured to control the mass flow controller to adjust the This magnitude of the gas flow and thereby the magnitude of the pressure drop is adjusted. The lithography apparatus of any one of claims 5 to 8, further comprising at least one of: (i) a pressure regulator configured to adjust the passage upstream of the flow restriction a gas pressure; (ii) a temperature sensor for sensing a temperature of the component; (iii) a downstream temperature sensor for measuring a gas in the path downstream of the component a temperature sensor; (iv) a pressure sensor configured to measure a gas pressure in the passage upstream of the flow restriction; (v) a heat exchanger configured to cause the gas to be at a certain Maintained in the passage upstream of the flow restriction at temperature; and (vi) any combination of the above. The lithography apparatus of claim 9, wherein the cooling controller is configured to perform at least one of: (i) varying a pressure setting of the pressure regulator and thereby varying the flow restriction Pressure drop; (ii) based on the temperature sensed by the temperature sensor Adjusting the pressure drop; (iii) adjusting the pressure drop based on the temperature measured by the downstream temperature sensor; and (iv) any combination of the above. The lithography apparatus of claim 9 or 10, further comprising a limit controller configured to limit the flow limiter when the pressure measured by the pressure sensor exceeds a certain value The gas pressure in the upstream passage. The lithography apparatus of any one of claims 1 to 11, wherein the component is a component of: (i) a substrate stage configured to support a substrate; (ii) a projection system; or Iii) A projection system top plate. A lithography apparatus according to any one of claims 1 to 12, configured to release gas from the downstream of the flow restriction into the apparatus. A method of cooling an element in a lithography apparatus, comprising: providing a gas stream through a gas passage and forcing the gas through a flow restricting member to expand and cool the gas; and directing the expanded and cooled gas to cool the gas One of the surfaces of the component to be cooled.